On SAGE Insight: Is the iPad Night Shift mode associated with poor sleep?

The increased use of self-luminous displays, (e.g. televisions, computer displays, cell phones and tablets) especially in the evening prior to bedtime, carries risks for adverse effects in humans, as has been associated with melatonin suppression, delayed sleep and sleep curtailment. Circadian disruption has been associated with poor sleep quality and has been linked to mood disorders, such as depression, and increased risks of chronic diseases such as diabetes, obesity, cardiovascular disease and cancer. This studyset out to investigate whether the Night Shift application provided by Apple Inc. for use on its portable electronic devices is effective for reducing acute melatonin suppression, a well-established marker of circadian phase.

Abstract

The increased use of self-luminous displays, especially in the evening prior to bedtime, has been associated with melatonin suppression, delayed sleep and sleep curtailment. The present study set out to investigate whether the Night Shift application provided by Apple Inc. for use on its portable electronic devices is effective for reducing acute melatonin suppression, a well-established marker of circadian phase. Participants experienced four experimental conditions: a dim light control, a high circadian stimulus true positive intervention and two Night Shift interventions delivering low and high correlated colour temperature light from the devices. Melatonin suppression did not significantly differ between the two Night Shift interventions, which indicates that changing the spectral composition of selfluminous displays without changing their brightness settings may be insufficient for preventing impacts on melatonin suppression.